Lake managers to discuss cyanotoxin reduction and quagga mussel control at national meeting in Denver

Upcoming seminars will address use of high-performance copper to reduce cyanotoxins and control quagga mussels in U.S. lakes and reservoirs.

DENVER – Lake managers from across the country will gather in Denver next month to discuss a double threat to U.S. lakes and reservoirs. The agenda for the annual meeting of the North American Lake Management Society (NALMS) includes seminars on reducing cyanotoxins and controlling invasive species. Cyanobacteria, quagga mussels and zebra mussels degrade water destined for treatment plants and hydropower facilities.

The recent discovery of quagga mussel larvae in an important Colorado reservoir raises alarms. The Green Mountain Reservoir in the Colorado-Big Thompson project sends water across the continental divide. Controlling quagga mussels here is critical to prevent their spread to other parts of the state and beyond.

Mounting evidence suggests that quagga mussels promote toxic cyanobacteria blooms. The invasive mussels consume green algae but allow cyanobacteria to flourish. Warm temperatures and high nutrient runoff from agriculture worsen matters. A recent survey found that 32 percent of national lakes tested positively for cyanotoxins. Reducing cyanotoxins is naturally a priority for lake managers, but there is a problem.

“Lake managers sometimes fear treatment,” said Dr. David Hammond, Senior Scientist for Earth Science Laboratories (ESL). “Conventional wisdom says that treatment causes dying cyanobacteria cells to spill toxins into the water where they are harder to remove. Our research suggests that low doses of ionic copper selectively target cyanobacteria without causing catastrophic cell rupture. Microbes that consume cyanotoxins remain unharmed. Properly designed treatment reduces the overall amount of cyanotoxin and the risk it poses.”

Hammond will lead two seminars at the upcoming NALMS meeting. The first will focus on reducing cyanotoxins. The second will focus on controlling quagga mussels and zebra mussels. Hammond will present data from case studies involving EarthTec®, for killing cyanobacteria, and EarthTec® QZ, for controlling zebra mussels. He will also be on hand to discuss the newly launched Cyanobacteria Rapid Response Program and Zebra Mussel Emergency Response Program. The zebra mussel program controls quagga mussels and zebra mussels.

More information on NALMS can be found at

Earth Science Laboratories Inc. manufactures advanced water treatment products. EarthTec and EarthTec QZ are EPA registered and NSF Certified to ANSI Standard 60 for use in drinking water. Both products are approved for use in open waters and in pipelines. Information about EarthTec and the Cyanobacteria Response Program is available at Visit to learn more about the Zebra Mussel Emergency Response Program.